Statistical Analysis of Solutions from the Sixth AIAA Computational Fluid Dynamics Drag Prediction Workshop.

A graphical framework is used for statistical analysis of the results from an extensive N-version test of a collection of Reynolds-averaged Navier-Stokes computational fluid dynamics codes. The solutions were obtained by code developers and users from North America, Europe, Asia, and South America using both common and custom grid sequences as well as multiple turbulence models for the June 2016 6 AIAA CFD Drag Prediction Workshop sponsored by the AIAA Applied Aerodynamics Technical Committee. The aerodynamic configuration for this workshop was the Common Research Model subsonic transport wing-body previously used for both the 4 and 5 Drag Prediction Workshops. This work continues the statistical analysis begun in the earlier workshops and compares the results from the grid convergence study of the most recent workshop with previous workshops. Most notably, the results reinforce a lesson learned from the 5 Drag Prediction Workshop regarding the importance of a common grid sequence in decreasing solution variation and demonstrate that predicted drag increments show less scatter between codes than the predicted absolute values of drag for a given configuration.